CentOS virt - Jul 2009 - Migrate windows VM from i386 Host to x86_64 host

Somehow one of our Xen servers ended up loaded with the i686 xen kernel, 
instead of the x86_64. The host has one windows VM running on it. The OS 
partition is file-based, but it also has a logical volume partition 
assigned for data. We would like to migrate the host server to a 64-bit 
kernel, which means moving the VM to one of our other 64-bit host 
servers. We tried simply copying the OS partition and using dd to move 
the LVM partition to a new host unsuccessfully. I'm pretty sure that dd 
may not be appropriate when moving between kernel architectures. 
However, even without the LVM partition specified in the vm config file, 
we are unable to boot the windows system. It looks like it is blue 
screening immediately, since we never get a console connection. Are 
there any instructions anywhere for moving VMs from one host 
architecture to another?

Current Host:
Centos 5.3 i686 kernel 2.6.18-128.2.1.el5
Xen 3.0.3-80.el5_3.3

Destination Host:
Centos 5.3 x86_64 kernel 2.6.18-128.2.1.el5
Xen 3.0.3-80.el5_3.3

Hi,

sounds strange.

Basically a dd should be enough to clone the machine.

I guess the hardware-model that gets through to the Windows-VM changes
when the Kernel-Achitecture changes.
So basically you swapped a 32-bit mainboard with a 64-bit mainboard - as
far as VM is concerned.

So I guess you have to "reapair" your Windows with some kind of
Windows-rescue-mode.

Which Windows is it?

With XP I had some success with booting from an install-media and then
going to "repair existing" after the install-process has detected the
already installed partition.

Afterwards all XP-patches had to be re-applied - though. But all
installed applications were still there.

You'd better try that procedure with cloned data...


Kind regards

Nils
 
> -----Original Message-----
> From: centos-virt-bounces at centos.org 
> [mailto:centos-virt-bounces at centos.org] On Behalf Of James Roman
> Sent: Thursday, July 30, 2009 3:24 PM
> To: Discussion about the virtualization on CentOS
> Subject: [CentOS-virt] Migrate windows VM from i386 Host to 
> x86_64 host
> 
> Somehow one of our Xen servers ended up loaded with the i686 
> xen kernel, instead of the x86_64. The host has one windows 
> VM running on it. The OS partition is file-based, but it also 
> has a logical volume partition assigned for data. We would 
> like to migrate the host server to a 64-bit kernel, which 
> means moving the VM to one of our other 64-bit host servers. 
> We tried simply copying the OS partition and using dd to move 
> the LVM partition to a new host unsuccessfully. I'm pretty 
> sure that dd may not be appropriate when moving between 
> kernel architectures. 
> However, even without the LVM partition specified in the vm 
> config file, we are unable to boot the windows system. It 
> looks like it is blue screening immediately, since we never 
> get a console connection. Are there any instructions anywhere 
> for moving VMs from one host architecture to another?
> 
> Current Host:
> Centos 5.3 i686 kernel 2.6.18-128.2.1.el5 Xen 3.0.3-80.el5_3.3
> 
> Destination Host:
> Centos 5.3 x86_64 kernel 2.6.18-128.2.1.el5 Xen 3.0.3-80.el5_3.3
> 
> 
> 
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